In an effort to ease the overall assembly and increase the portability of wheelchairs, the industry has experienced substantial design changes in recent years. Many individual components are now designed for interchangeability and formed for releasable mounting to their respective mounting structures.
Armrests, for example, are often releasably secured a portion of a wheelchair frame through an armrest mounting assembly which is rigidly affixed to the frame. Typically, an armrest assembly includes an armrest pad which is mounted to an inverted, U-shaped, armrest support frame. This armrest support frame includes a generally horizontal tube portion, which supports the pad, and includes a pair of downwardly extending post portions. Each post portion is usually oriented in a substantially vertical manner for ease of installation and removal from the mounting assembly. Each armrest mounting block or assembly generally is provided by a body which has post receiving opening therein. The post receiving openings are dimensioned to receive the distal ends of the corresponding post portions. By slightly tapering each armrest post end, the post ends gradually wedge or snugly seat against the inner walls of the mounting block as the post ends are pushed down into the armrest mounting blocks.
Wheelchairs generally include a seat assembly mounted to the wheelchair frame and two armrests mounted adjacent to and on opposing sides of the seat assembly. Each armrest requires at least two mounting assemblies or blocks positioned in a spaced-apart relation on one side of the seat assembly, which blocks mount the armrest support frame to the wheelchair frame. These mounting assemblies are usually fixedly mounted to the wheelchair frame at predetermined positions by fasteners, such as bolts. The bolts extend through mounting apertures provided in the mounting assembly or block body. Additionally, aligned apertures are provided in the wheelchair frame so that fasteners extending through the mounting blocks and frame rigidly affix the mounting assembly to the frame. Since the spacing of the armrest mounting assemblies is fixed by fasteners to the frame, the spacing between the downwardly depending post portions of the armrest frame typically must be slightly adjusted to achieve proper alignment between the post ends and the corresponding post receiving apertures of the mounting blocks.
Usually, armrest post ends must be physically bent into alignment with the armrest mounting blocks. This procedure is adequate, but it can be time-consuming and is based upon a trial and error technique. Moreover, the wheelchair user also can experience armrest misalignment difficulties if they remove and re-install the armrests, particularly if the armrest assembly should be dropped during handling. Should this occur, substantial bending may again be required in order to re-install the armrest. This problem can be magnified for those users who are severely physically impaired.
Another problem associated with prior armrest mounting assemblies is that they do not facilitate interchangeability of the armrests. Sometimes, the user may find it desirable to increase or decrease the length of the armrest support frame. With the current mounting assemblies, however, once they are mounted to the wheelchair frame, only those armrests having post ends properly corresponding to the distance between the post receiving apertures of the mounting assemblies may be installed. Another armrest having a horizontal tube portion which is skewed or out of alignment by as little as one-quarter an inch different in length by that amount or less would require either substantial bending of the posts or remounting of one of the mounting assemblies to the wheelchair frame to accommodate the distance change between the posts. Such substantial bending the posts would be subject to the problems already mentioned above.
Accordingly, it is an object of the present invention to provide an armrest mounting assembly which provides ease of adjustment of the alignment of the mounting assemblies to the spacing of the armrest posts.
It is another object of the present invention to provide an armrest mounting assembly which eases installation and removal of the armrest.
Still another object of the present invention is to provide an armrest mounting assembly which promotes interchangeability between the armrests.
It is a further object of the present invention to provide an armrest mounting assembly which is durable, compact, easy to maintain, has a minimum number of components, is easy to use by unskilled personnel, and is economical to manufacture.
The apparatus of the present invention has other objects and features of advantage which will be more readily apparent from the following description of the Best Mode of Carrying Out the Invention and the appended claims, when taken in conjunction with the accompanying drawing.